如何在使用XSL合并后处理来自多个XML文件的所有数据

I am using XSL to read in three XML documents which are identical except their attributes have different values (potentially I will be reading many XML files). I want to count the number of times the "outcome" attribute has a value "Passed" or "Failed" for the element whose "testName" attribute = "TestOne". I am achieving this using the following:I am using XSL to read in three XML documents w